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Old August 7th 03, 03:01 PM
Pete KE9OA
 
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Drake doesn't use them in everything up to the R7/R8 series, but they do use
them in the SW1, SW2, and the SW8. Although the ceramic filter route is the
cheaper way to go, vs. LC circuits or crystal/mechanical filters at the
final I.F. some enhanced steepness on the curves can be obtained by using a
good roofing filter at the 1s I.F.
On another note...........if you look at Murata's specs, especially for the
CFU/CFWS series, you will see that the C.F. is specified at (plus or minus
two kHz). Still not a show stopper; that is probably a big reason that the
AOR7030 has that self alignment function, whereby the filters are swept, and
probably, the 2nd LO is warped to provide symmetrical response.

Pete

Mike Maghakian wrote in message
om...
also the fact that you use excellent drake receivers means you know
that these receivers I mention use cheap filters and that shape
factors are important. If drake used filters like the receivers I
mentioned they would not be the classics they are today.

N8KDV wrote in message

...
Mike Maghakian wrote:

most receivers don't come with adequate selectivity. now for a small
amount and with a bit of skill you can change that. check out the
LF-D6 ceramic filter on my web page.

http://maghakian.home.att.net/


Oh yes. what receiver(s) are you proposing that these filters be put in?